The use of troughs to water farm animals is common place. Troughs normally have a system for automatically replenishing water consumed by animals such as a valve connected to a ball-cock mechanism.
The exposed nature of conventional troughs means the water within the trough may become contaminated by outside matter such as sprays and fertiliser. The exposed nature of the trough also promotes algae growth which can foul the water or make the trough undesirable for animals to drink from. Foreign bodies such as branches, plant matter, rubbish, bird droppings and so forth, may also be introduced to the trough and increase the risk of bacteria, such as Salmonella or Botulism, being passed to the animals drinking from the trough. As a consequence, the troughs must be cleaned and foreign matter removed, which can at times be time consuming and labourious.
Attempts have been made to provide a trough that protects the water from foreign debris. An example of an attempt can be found in U.S. Pat. No. 4,003,340. This patent discloses a stock watering trough that is kept covered at all times when not in use by a pair of floating lid sections hingedly attached on opposite sides of a centre support within the trough. The lid sections have a crowned configuration that results in the marginal edges of the lid sections being immersed below the level of the water upon which they float. While this invention overcomes a number of the problems associated with trough contamination, the lids cannot be retrofitted with ease to existing troughs. The farmer must either perform considerable alterations on existing troughs, or buy a new unit, which may be very expensive.
U.S. Pat. No. 4,739,727 discloses an animal waterer having an insulated container for holding water, a supply conduit for supplying water under pressure to the container and a valve connected to the supply conduit for maintaining the water in the container substantially at a predetermined level. An insulated lid is sealingly attached to the top of the container and has a pair of openings in it each large enough to permit an animal to extend its mouth through for the purpose of drinking water from the container. A flexible length member extends between and is rotatably attached to two closure members at each end of the length and is used to close off the openings in the container. A biasing structure, preferably a cable extending over a pulley and having a weight attached to one end, where the other end is attached to an intermediate part of a link member, holds the closure members against the bottom of the openings the container to keep them closed at all times except when an animal is pushing them down to drink from the container. The apparatus of this invention is complex and difficult to install.
Farm animals require regular watering, and often need to receive medical or nutritional supplements, such as minerals and zinc. Therefore, the provision of a supplement dispensing device within a trough may be advantageous.
It is convenient to dispense treatment substances, such as medicaments or nutrients via the animals drinking water in such a trough. It may also be desirable to release the substance into the water over time, rather than simply mixing the substance into the water, as correct concentrations may need to be maintained over time. It is also inconvenient to have to continually go to troughs and top up the substance volume.
Some attempts have been made to provide a means of slowly dispensing a substance in a trough New Zealand Patent No. 260398 provides a bag or a sock into which a substance can be introduced, wherein the bag is placed in a trough for slow release of the substance. However, the problems associated with debris, algae, and other foreign contamination of the water still persist.
The ball-cock mechanisms used in the troughs to maintain the water level are often damaged by farm animals drinking from the trough. This may lead to the water valve remaining on and causing water wastage, or remaining off and causing the trough to dry up.